How cover crops help your combine roll through waterlogged fields

Here's another benefit from growing a wide array of cover crops in your no-till or minimum tillage system: That deep-rooted network reaching down from multiple cover species builds a firmer soil profile.

When your combine and grain cart absolutely, positively must get through before corn goes down, you can roll. Even through standing water.

November 5, 2018  By Jerry Carlson — Many farmers are facing that muddy challenge during this fall's waterlogged harvest.

Conventional tillage without cover crops generates a sloppy top few inches of soil, underlain with a waterproof, rootproof density layer. Such soils are often so sticky on top that the mud builds up on rubber tracks. The tracks stop floating and start bulldozing. In our northern Iowa neighborhood, we've been hearing that a few farmers are trading in their tracked grain carts for those with floater tires.

So yesterday when the following photo of the big Claas/Lexion combine and grain cart arrived from Indiana, I presumed that my friend Hal Brown was showing me one of those classic photos of a humongous combine buried in mud. Instead, Hal was successfully harvesting a waterlogged 134-acre field — which averaged 224 bu. per acre. That included 34 acres of standing water as deep as 18 inches. 

That combine isn't stuck, it's rolling through mud, carrying a 40-foot Drago corn head through 200-bu. plus corn.
This photo was shot from the mud-spattered rear window of the tractor pulling a grain cart.

Hal's harvest team unloaded into grain carts on the go. By limiting each grain cart to 500 bu., "The cart didn't leave much of a rut anywhere in the field," said Hal.

Compaction? No problem. He says, "When soil is completely saturated, all pore space is full of water and field traffic doesn't cause long-term compaction." He cites rice growers who typically incorporate rice stubble in paddies with standing water. And all across Asia, rice growers plow and stir paddies before planting. 

By pushing corn harvest through the rainy stretch, Windy Lane Farms avoided dropped ears and the potential for severe lodging of soggy stalks carrying heavy ears of corn. 

View from a tractor pulling a grain cart through standing water.
The tracked Claas combine and tracked carts wallowed through
ponded areas as deep as 18 inches. No deep ruts under the cart.

Hal's long-term management plan of cover crops on every acre has — over several years — built a foundation of firm but porous soil laced together with fibrous cover-crop roots. "The name of the cover-crop game is diversity," he observes from long experience. Covers are his third or fourth crop of every season. Here's a link to a report on other reasons for diversifying the mix of legumes and grasses in cover crops.

Deep-penetrating cover crop roots gradually break up any old "plow layer" from previous years of tillage. Thus a firm seedbed doesn't mean one that corn and soybean roots can't penetrate. Hal puts it this way: "Cover crop roots do a better job of tillage than steel can ever do."

He says, "This fall in our area of Indiana, corn and soybean growers on conventionally tilled ground with no history of cover crops have faced repeated, long harvest delays."

Farmers who go the no-till route without cover crops on prairie soils have found minimal relief from the old embedded density layers. Those who've worked out their management systems to include diverse cover crops have seen far less "pancake" rooting in their corn, as corn roots follow the vertical pathways opened up by deep-rooted cover species. 

With 7,000 acres of corn and soybeans to cover, Windy Lane Farms needs to keep rolling. The farm's cover-crop program has been featured in Farm Journal. Here's a link to the PDF story from their farm. (Author of that report is Stephanie Larson.)

You can find a growing array of cover-crop experts who offer webinars and other courses on the best blends for each region, each soil and each following crop. Hal says he has studied most of those sources. But his most valuable observations come from experience which he and his son Ty have accumulated on their own land over the years. He accelerates the learning curve over the winter by planting cover mixes in a heated shop, under grow lights, and observing root development. 

One cover-crop experiment, under LED lights, in Hal's shop
Root research growth chambers. Each side is removable.
Soil profile stays in place when one side is temporarily removed.

Even the experts don't have all answers to the underground communication between roots of multiple species in the same soil. Some species are allelopathic against certain others, including the following cash crop. They exude hormones constraining growth of neighboring roots. Other species are mutually beneficial. Some encourage healthy mycorrhizae fungus while still others favor beneficial bacteria. Since the combinations of legumes and grasses are nearly infinite, experiments of your own can help zero in on the most vigor-inducing mixes. 

One of Hal's trial runs in his shop growth chambers is the nearby mix of common vetch, winter lentils and Austrian winter peas. (Incidentally, the chicken wire around the three columns containing covers and soil is not to support the tall mix of maturing covers. "It's to keep the cat from digging in the dirt around my experiment," says Hal.)

Last winter and spring we used clear plastic tubes as "terrarium" root growth chambers to compare corn root growth under varying mixes of microbial products and hormones, some of them mobilized with WakeUP Spring. It became clear that a 24-inch deep tube isn't long enough; the most vigorous corn roots soon hit bottom.

Hal's answer for cover crop research overwinter is pictured nearby: deep, rectangular growth chambers constructed of wood. A wooden panel on each side is removable to observe how roots grow in each cover-crop mix.

One more idea which Windy Lane Farms uses to establish cover crops: The combine in our photo (below, right) carries a Horsch air seeder which delivers cover crop seed uniformly under the header.  The seed is fed from a hopper mounted on the rear of the combine, which you can see in the photo shot from a following tractor. We ran a more detailed photo of this Horsch seeder in an earlier report at this link

Air seeder hopper mounts on rear of combine

Also — note again that the grain cart in front of this tractor is cruising through standing water without cutting a deep rut. Only the smaller rear wheels of the big combine are leaving much of a mark, and compaction will be minimal in saturated soil.

Many farmers back away from continually experimenting and enhancing biological life in the soil — using cover crops as a major tool. No major corporation offers a formula for that, in the way NPK/herbicides/pesticides are a formula. Maybe the corporations would — if cover blends could be patented and priced high. Fortunately there's an abundance of information on covers and soil health for anyone eager to absorb it. That takes one of the rarest and most powerful ingredients in farming: passion. Enthusiasm and focus which make the pursuit of soil health exciting.

Windy Lane Farms work shirt

Hal and Ty Brown's team literally wear that enthusiasm. They offer all family members and employees red work shirts like the one shown in the nearby photo. It carries the Windy Lane Farm motto: Farming with Passion

That's the same message I heard from another enthusiast for cover crops and no-till: North Dakota farmer/rancher Gabe Brown (not a relative of Hal Brown). I had asked Gabe how he gets everything done on about 5,000 acres, along with making many exhausting speaking tours. He said, "My family is passionate about soil health." His operation is labeled Living Web Farms.

Historically, a dominant share of great discoveries have arisen from individuals who researched and explored unknown realms of science with persistent passion. Examples: Louis Pasteur, Marie Curie, Nikola Tesla, Nicolaus Copernicus, and Dr. Max Gerson to name a few. Today we'd add more, like William Albrecht, Anthony Samsel, Don Huber, Robert Kremer. Usually such innovators battle fierce skepticism, even hostile opposition, from defenders of the conventional wisdom of their day.

At Renewable Farming, we love working with farmers who are passionate about their profession of renewing soil health and human health. Even in the current market climate, they're persistently enthused, and they encourage all those around them.